JPS5842256Y2 - food packaging tray - Google Patents

Description

[Detailed description of the invention] The present invention relates to a food packaging tray, and more specifically, the food packaging tray is made of a thermoplastic foam resin alone or in a laminated state with a non-foamed thermoplastic resin. The present invention relates to a tray that has sufficient strength against bending and longitudinal expansion and contraction of the side walls.

In conventional food packaging trays, in order to maintain strength against bending stress F1 applied to the inner side of the side wall during packaging,
The solution was to be solved by providing a rib structure inside the side wall or at the connecting corner between the bottom plate and the side wall, or by making it thicker, but recently the speed of packaging machines has increased, packaging methods have changed, and the performance of shrink film has improved. There is a bending stress F in the inward direction, and a force F that tries to push outward.
2 acts, the inner and outer bending stress F1.2 acts on these side walls. It was desired to devise a reinforcing structure to maintain sufficient strength against F2.

In view of these conventional problems, the inventor of the present invention has attempted to solve the problems, and aims to improve the side walls and/or
Alternatively, this objective was achieved by forming ribs protruding from the inside and outside of the bottom plate, and by interposing flat plate portions between adjacent ribs.

The details of the present invention will be explained based on an illustrated embodiment.
In the figure, 1 is a food packaging tray made of thermoplastic foamed resin such as styrene paper alone or in a laminated state with non-foamed thermoplastic resin. The filling is housed and wrapped with shrink film.

In the present invention, the food packaging tray 1 is provided with reinforcing ribs 4 on the surface of the side wall 2 and/or the bottom plate 3 and on the outer surface, that is, on the inside and outside of the food packaging tray 1, and the adjacent ribs 4, A flat plate portion 4' is interposed between the tray side walls 2 to provide sufficient strength against bending inward and outward directions of the tray side wall 2 and expansion and contraction in the longitudinal direction of the side wall.

The reinforcing ribs 4 can be provided only on the side walls 2 or only on the bottom plate 3, but by providing them from the side walls 2 to the ends of the bottom plate 3, the strength in the inner and outer directions can be increased. This is more promising than when it is provided only on the side wall 2 and bottom plate 3.

Further, the reinforcing ribs 4 may be formed so that the inner and outer sides are respectively placed, but the reinforcing ribs 4 are formed when stacking to prevent the height from increasing when a large number of main packaging trays 1 are stacked. A structure in which the inner and outer parts 4 can be fitted into each other, for example, an uneven structure with an inner and outer corrugated cross section as shown in FIGS. 3 to 6, is adopted.

In the case shown in FIG. 8, the inner and outer ribs 4 are connected to the side wall 2 of the tray.
and protrudes from the connecting corner of the bottom plate 3, and the present invention allows these embodiments to be selected as appropriate.

In addition, if the double-sided vacuum forming method of Patent Application Publication No. 148863 of 1974 is adopted to provide the reinforcing ribs 4 on the inside and outside of the tray, the concave grooves on the back side will be accurate when creating the uneven shape inside and outside, especially the wavy rib. It is possible to set the height when stacking so that it does not become too high.

Therefore, when the food packaging tray according to the present invention is used for packaging various foods, bending stress F1 is applied to the tray side walls 2, 2 inwardly and outwardly when filling the contents and packaging the food.
．． Even if F2 is used, the tray 1 of the present invention has reinforcing ribs 4 on the side walls 2 and/or the bottom plate 3, so that sufficient support strength can be obtained and the distance between adjacent reinforcing ribs 4. Since a flat plate part 4' is always formed between the ribs 4, even if a load is applied to the tray side wall 2 in the direction of expansion or contraction in the length direction, the flat plate part 4'...
・It can exhibit extremely high anti-stretch properties and prevent expansion/contraction deformation compared to when it is formed continuously, so it prevents so-called post-deformation during food storage or after molding, and it also makes the entire tray shape-retentive. This is effective enough to ensure security.

Furthermore, even when a large number of trays 1 are stacked, when the back surface of the rib 4 is a concave portion, the convex portion of the rib fits with the back surface of the rib of another tray, making it possible to stack the trays without increasing the stacking height. It is.

Examples are described below.

Foamed polystyrene raw fabric (average thickness 2.1 M, basis weight 17)
5g/7712) was heated and plasticized in a far-infrared heating furnace with an internal temperature of 180℃, and the depth was 22M1 and the length of the long side was 196fl!
A tray with a short side length of 9971 m as shown in FIG. 1 and a tray without ribs were prepared, and the strength of the molded products and the stacking height were compared, and the results were as follows.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional tray, FIG. 2 is a perspective view of a food packaging tray according to the present invention, FIGS. 3 to 6 are enlarged partial sectional views of ribs, and FIG. AA sectional view of the figure,
FIG. 8 is a perspective view of another food packaging tray according to the present invention. 1... Tray, 2... Side wall, 3... Bottom plate, 4...
・Rib, F... Bending stress inward direction, F2...
Bending stress in the outward direction.

Claims (1)

[Scope of utility model registration request] A food packaging tray, in which reinforcing ribs are alternately provided on the inside and outside of a side wall and/or a bottom plate, and a flat plate is interposed between each reinforcing rib.